What is the reason for the nightmares and disturbing dreams that afflict me when I sleep without completing the remembrances of sleep?

To overcome frightening visions: Perform ablution before sleeping and pray, then recite the complete sleep adhkār (supplications) with certainty that Allah is the Preserver, and that these adhkār are a means of preservation. If you wake up due to a frightening vision, follow the instructions mentioned in Fatwa no. 35254.